U.S. patent application number 10/385461 was filed with the patent office on 2003-12-25 for organic luminescence device.
This patent application is currently assigned to CANON KABUSHIKI KAISHA. Invention is credited to Senoo, Akihiro, Suzuki, Koichi, Ueno, Kazunori.
Application Number | 20030235713 10/385461 |
Document ID | / |
Family ID | 26621534 |
Filed Date | 2003-12-25 |
United States Patent
Application |
20030235713 |
Kind Code |
A1 |
Suzuki, Koichi ; et
al. |
December 25, 2003 |
Organic luminescence device
Abstract
In an organic luminescence device formed of one or plural layers
of organic films between an anode and a cathode, at least one layer
is any one of a luminescence layer, an electron injection layer and
an electron-transporting layer and is formed of at least a spiro
compound of formula (I-a) or (I-b) having a carbon atom or a
silicon atom as a spiro atom and having four ring structures
including at least one nitrogen atom-containing ring structure. By
the use of the spiro compound of the formula (I-a) or (I-b), the
resultant organic luminescence device produces a high-luminance
fluorescent luminescence at a low voltage for a long period of
time.
Inventors: |
Suzuki, Koichi;
(Yokohama-shi, JP) ; Senoo, Akihiro;
(Kawasaki-shi, JP) ; Ueno, Kazunori; (Ebina-shi,
JP) |
Correspondence
Address: |
FITZPATRICK CELLA HARPER & SCINTO
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Assignee: |
CANON KABUSHIKI KAISHA
|
Family ID: |
26621534 |
Appl. No.: |
10/385461 |
Filed: |
March 12, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10385461 |
Mar 12, 2003 |
|
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PCT/JP02/08803 |
Aug 30, 2002 |
|
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Current U.S.
Class: |
428/690 ;
313/504; 313/506; 428/917 |
Current CPC
Class: |
H01L 51/0038 20130101;
H01L 51/0039 20130101; H01L 51/0078 20130101; C09K 11/06 20130101;
H01L 51/004 20130101; H01L 51/0042 20130101; Y10S 428/917 20130101;
H01L 51/005 20130101; H01L 51/0053 20130101; H01L 51/0094 20130101;
H01L 51/0069 20130101; C08G 61/12 20130101; H01L 51/0043 20130101;
H01L 51/0036 20130101; H01L 51/0058 20130101; H01L 51/007 20130101;
H01L 51/0071 20130101; H01L 51/0035 20130101; C08G 61/02 20130101;
H01L 51/0059 20130101; H01L 51/0034 20130101; H01L 51/5048
20130101; H01L 51/5092 20130101; C08G 61/123 20130101; H01L 51/0052
20130101; H01L 51/5012 20130101; H01L 51/0077 20130101; H01L
51/0081 20130101; H05B 33/14 20130101 |
Class at
Publication: |
428/690 ;
428/917; 313/504; 313/506 |
International
Class: |
H05B 033/12 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 3, 2001 |
JP |
265871/2001 |
Oct 2, 2001 |
JP |
306084/2001 |
Claims
1. An organic luminescence device, comprising: a pair of an anode
and a cathode, and at least one organic layer disposed between the
anode and the cathode, wherein said at least one organic layer
comprises a layer comprising at least one species of a compound
represented by the following formula (I-a): 40wherein K.sub.1,
K.sub.2, K.sub.3 and K.sub.4 independently denote a substituted or
unsubstituted aromatic ring or a substituted or unsubstituted
heterocyclic ring, at least one of K.sub.1, K.sub.2, K.sub.3 and
K.sub.4 being a heterocyclic ring containing at least one nitrogen
atom; and L.sub.1, L.sub.2, L.sub.3 and L.sub.4 independently
denote a hydrogen atom, an alkyl group, a substituted or
unsubstituted aralkyl group, a substituted or unsubstituted aryl
group, a substituted or unsubstituted heterocyclic group, an alkoxy
group, a nitro group, a substituted or unsubstituted amino group,
or a group represented by any one of the following formulas (X),
(XI) and (XII): 41wherein R.sub.5 to R.sub.15 independently denote
a hydrogen atom, an alkyl group, a substituted or unsubstituted
aralkyl group, a substituted or unsubstituted aryl group, a
substituted or unsubstituted heterocyclic group, or a nitro group;
X.sub.1 to X.sub.3 and Y, to Y.sub.3 independently denote a
nitrogen atom or C--R.sub.16 where R.sub.16 denotes a hydrogen
atom, an alkyl group, a substituted or unsubstituted aralkyl group,
or a substituted or unsubstituted aryl group; Z.sub.1 to Z.sub.3
independently denote --O--, --S--, --NR.sub.17--,
--Si(R.sub.18)R.sub.19--, --C(R.sub.20)R.sub.21--, --CH.dbd.CH-- or
--CH.dbd.N--, in which R.sub.17, R.sub.20 and R.sub.21
independently denote a hydrogen atom, an alkyl group, a substituted
or unsubstituted aralkyl group, a substituted or unsubstituted aryl
group, or a substituted or unsubstituted heterocyclic group; and
R.sub.18 and R.sub.19 independently denote an alkyl group, a
substituted or unsubstituted aralkyl group, a substituted or
unsubstituted aryl group, or a substituted or unsubstituted
heterocyclic group; l and p are respectively 0 or 1; m and n are
respectively 0 or an integer of 1-30, with the proviso that m+n is
an integer of 1-30; and q and r are respectively an integer of
2-30.
2. An organic luminescence device according to claim 1, wherein
said compound of the formula (I-a) is a compound represented by any
one of the following formulas (II-a) to (IX-a): 4243wherein R.sub.1
to R.sub.4 independently denote a hydrogen atom, an alkyl group, a
substituted or unsubstituted aralkyl group, a substituted or
unsubstituted aryl group, a substituted or unsubstituted
heterocyclic group, an alkoxy group, a nitro group, or a
substituted or unsubstituted amino group.
3. An organic luminescence device according to claim 1, wherein at
least one of L.sub.1 to L.sub.4 is said it group represented by any
one of the formulas (X), (IX) and (XII).
4. An organic luminescence device according to claim 1, wherein
said layer comprising at least one species of the compound of the
formula (I-a) comprises an electron injection layer, an
electron-transporting layer or a luminescence layer.
5. An organic luminescence device, comprising: a pair of an anode
and a cathode, and at least one organic layer disposed between the
anode and the cathode, wherein said at least one organic layer
comprises a layer comprising at least one species of a compound
represented by the following formula (I-b): 44wherein K.sub.1,
K.sub.2, K.sub.3 and K.sub.4 independently denote a substituted or
unsubstituted aromatic ring or a substituted or unsubstituted
heterocyclic ring, at least one of K.sub.1, K.sub.2, K.sub.3 and
K.sub.4 being a heterocyclic ring containing at least one nitrogen
atom; and L.sub.1, L.sub.2, L.sub.3 and L.sub.4 independently
denote a hydrogen atom, an alkyl group, a substituted or
unsubstituted aralkyl group, a substituted or unsubstituted aryl
group, a substituted or unsubstituted heterocyclic group, an alkoxy
group, a nitro group, a substituted or unsubstituted amino group,
or a group represented by any one of the following formulas (X),
(XI) and (XII): 45wherein R.sub.5 to R.sub.15 independently denote
a hydrogen atom, an alkyl group, a substituted or unsubstituted
aralkyl group, a substituted or unsubstituted aryl group, a
substituted or unsubstituted heterocyclic group, or a nitro group;
X.sub.1 to X.sub.3 and Y, to Y.sub.3 independently denote a
nitrogen atom or C--R.sub.16 where R.sub.16 denotes a hydrogen
atom, an alkyl group, a substituted or unsubstituted aralkyl group,
or a substituted or unsubstituted aryl group; Z.sub.1 to Z.sub.3
independently denote --O--, --S--, --NR.sub.17--,
--Si(R.sub.18)R.sub.19--, --C(R.sub.20)R.sub.21--, --CH.dbd.CH-- or
--CH.dbd.N--, in which R.sub.17, R.sub.20 and R.sub.21
independently denote a hydrogen atom, an alkyl group, a substituted
or unsubstituted aralkyl group, a substituted or unsubstituted aryl
group, or a substituted or unsubstituted heterocyclic group; and
R.sub.18 and R.sub.19 independently denote an alkyl group, a
substituted or unsubstituted aralkyl group, a substituted or
unsubstituted aryl group, or a substituted or unsubstituted
heterocyclic group; l and p are respectively 0 or 1; m and n are
respectively 0 or an integer of 1-30, with the proviso that m+n is
an integer of 1-30; and q and r are respectively an integer of
2-30.
6. An organic luminescence device according to claim 5, wherein
said compound of the formula (I-b) is a compound represented by any
one of the following formulas (II-b) to (IX-b): 46wherein R.sub.1
to R.sub.4 independently denote a hydrogen atom, an alkyl group, a
substituted or unsubstituted aralkyl group, a substituted or
unsubstituted aryl group, a substituted or unsubstituted
heterocyclic group, an alkoxy group, a nitro group, or a
substituted or unsubstituted amino group.
7. An organic luminescence device according to claim 5, wherein at
least one of L.sub.1 to L.sub.4 is said group represented by any
one of the formulas (X), (IX) and (XII).
8. An organic luminescence device according to claim 5, wherein
said layer comprising at least one species of the compound of the
formula (I-b) comprises an electron injection layer, an
electron-transporting layer or a luminescence layer.
Description
TECHNICAL FIELD
[0001] The present invention relates to an organic
(electro-)luminescence device and particularly to an organic
luminescence device for emitting light by applying an electric
field to a film of an organic compound (organic compound
layer).
BACKGROUND ART
[0002] An organic luminescence device generally comprises a pair of
electrodes (comprising an anode and a cathode) and a film
comprising a fluorescent organic compound disposed between the
electrodes. Into the organic compound layer (film), holes and
electrons are injected from the anode and the cathode,
respectively, thus forming excitons of the fluorescent organic
compound. When the excitons are returned to ground state, the
organic luminescence device emits light or causes luminescence.
[0003] According to a study by Eastman Kodak Co. ("Appl. Phys.
Lett.", vol. 51, pp. 913-(1987)), it has been reported that a
function-separation type organic luminescence layer comprising
mutually laminated two layers including a layer of an aluminum
quinolinol complex (as an electron transporting and luminescent
material) and a layer of a triphenylamine derivative (as a hole
transporting material) causes luminescence at a luminance
(brightness) of ca. 1,000 cd/m.sup.2 under application of a voltage
of ca. 10 volts. This is also reported in, e.g., U.S. Pat. Nos.
4,539,507; 4,720,432 and 4,885,211.
[0004] Further, by changing species of the fluorescent organic
compound, it is possible to effect luminescence over broad
wavelength regions ranging from an ultraviolet region to an
infrared region. In this regard, various compounds have been
extensively studied in recent years. Such compounds have been
proposed in, e.g., U.S. Pat. Nos. 5,151,629, 5,409,783 and
5,382,477, and Japanese Laid-Open Patent Applications (JP-A)
2-247278 (corr. to U.S. Pat. Nos. 5,130,603 and 6,093,864), JP-A
3-255190 (corr. to U.S. Pat. No. 5,227,252), JP-A 5-202356, JP-A
9-202878 and JP-A 9-227576.
[0005] In addition to the above-mentioned organic luminescence
devices using low-molecular weight materials, an organic
luminescence device using a conjugated polymer has been reported by
a research group of Cambridge University ("Nature", vol. 347, pp.
539-(1990)). According to this report, a signal layer of
polyphenylenevinylene (PPV) is formed through a wet-coating process
and luminescence from the single layer is confirmed. Such an
organic luminescence device using a conjugated polymer has also
been proposed by, e.g., U.S. Pat. Nos. 5,247,190, 5,514,878 and
5,672,678, JP-A 4-145192 (corr. to U.S. Pat. Nos. 5,317,169 and
5,726,457), and JP-A 5-247460.
[0006] As described above, recent progress in organic luminescence
device is noticeable, and the resultant organic luminescence
devices are characterized by high luminance (brightness) under
application of a low voltage, various (light-)emission wavelengths,
high-speed responsiveness, small thickness and light weight, thus
suggesting possibility of wide applications.
[0007] However, the above-described organic luminescence devices
are still required to effect light output (emission) at a higher
luminance and/or a higher conversion efficiency in the present
state. These organic luminescence devices are also still
insufficient in terms of durability such that the devices are
liable to be changed in their properties with time when used for a
long period or liable to be deteriorated by the influence of
ambient air containing oxygen or of humidity. Further, in the case
of using the organic luminescence devices for full-color display,
it is necessary to effect luminescences of blue, green and red with
good color purities. However, a satisfactory solution to the
problem has not been realized yet, and particularly a red
luminescence with a good color purity has not been satisfactorily
provided.
[0008] On the other hand, spiro compounds having a unique
three-dimensional structure and unique material properties have
been noted as an organic functional material (J. Am. Chem. Soc.
110, p. 5687-(1988)). A proposal of using a spiro compound in an
organic luminescence device has been reported (JP-A 7-278537) but
has failed to provide an electron-transporting layer or a
luminescence layer exhibiting sufficient luminescence
performance.
DISCLOSURE OR INVENTION
[0009] A generic object of the present invention is to provide
improvements to problems an mentioned above encountered in organic
luminescence devices proposed heretofore.
[0010] A more specific object of the present invention is to
provide an organic (electro-) luminescence device capable of
effecting light output (emission) at high efficiency and luminance
while realizing a prolonged life.
[0011] Another object of the present invention is to provide an
organic luminescence device capable of providing a wide variety of
emission wavelengths and emission hues, inclusive of particularly
orange and red hues, and a good durability.
[0012] A further object of the present invention is to provide an
organic luminescence device which can be produced easily and
relatively inexpensively.
[0013] According to the present invention, there is provided an
organic luminescence device, comprising:
[0014] a pair of an anode and a cathode, and
[0015] at least one organic layer disposed between the anode and
the cathode, wherein
[0016] the above-mentioned at least one organic layer comprises a
layer comprising at least one species of a compound represented by
the following formula (I-a): 1
[0017] wherein K.sub.1, K.sub.2, K.sub.3 and K.sub.4 independently
denote a substituted or unsubstituted aromatic ring or a
substituted or unsubstituted heterocyclic ring, at least one of
K.sub.1, K.sub.2, K.sub.3 and K.sub.4 being a heterocyclic ring
containing at least one nitrogen atom; and
[0018] L.sub.1, L.sub.2, L.sub.3 and L.sub.4 independently denote a
hydrogen atom, an alkyl group, a substituted or unsubstituted
aralkyl group, a substituted or unsubstituted aryl group, a
substituted or unsubstituted heterocyclic group, an alkoxy group, a
nitro group, a substituted or unsubstituted amino group, or a group
represented by any one of the following formulas (X), (XI) and
(XII): 2
[0019] wherein
[0020] R.sub.5 to R.sub.15 independently denote a hydrogen atom, an
alkyl group, a substituted or unsubstituted aralkyl group, a
substituted or unsubstituted aryl group, a substituted or
unsubstituted heterocyclic group, or a nitro group;
[0021] X.sub.1 to X.sub.3 and Y.sub.1 to Y.sub.3 independently
denote a nitrogen atom or C--R.sub.16 where R.sub.16 denotes a
hydrogen atom, an alkyl group, a substituted or unsubstituted
aralkyl group, or a substituted or unsubstituted aryl group;
[0022] Z.sub.1 to Z.sub.3 independently denote --O--, --S--,
--NR.sub.17--, --Si(R.sub.18)R.sub.19--, --C(R.sub.20)R.sub.21--,
--CH.dbd.CH-- or --CH.dbd.N--, in which R.sub.17, R.sub.20 and
R.sub.21 independently denote a hydrogen atom, an alkyl group, a
substituted or unsubstituted aralkyl group, a substituted or
unsubstituted aryl group, or a substituted or unsubstituted
heterocyclic group; and R.sub.18 and R.sub.19 independently denote
an alkyl group, a substituted or unsubstituted aralkyl group, a
substituted or unsubstituted aryl group, or a substituted or
unsubstituted heterocyclic group;
[0023] 1 and p are respectively 0 or 1;
[0024] m and n are respectively 0 or an integer of 1-30, with the
proviso that m+n is an integer of 1-30; and
[0025] q and r are respectively an integer of 2-30.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIGS. 1 to 4 are schematic sectional views each illustrating
a basic structure of an organic luminescence device according to an
embodiment of the present invention.
BEST MODE FOR PRACTICING THE INVENTION
[0027] The organic luminescence device according to the present
invention is characterized in that at least one organic (compound)
layer disposed between the pair of electrodes (anode and cathode)
includes a layer comprising at least one species of a spiro
compound represented by the above-mentioned formula (I-a) or
(I-b).
[0028] In the case of using the spiro compound of the formula (I-a)
having a carbon atom as a spiro atom, the spiro compound may
preferably be a compound represented by any one of the following
formulas (II-a) to (IX-a): 34
[0029] wherein R.sub.1 to R.sub.4 independently denote a hydrogen
atom, an alkyl group, a substituted or unsubstituted aralkyl group,
a substituted or unsubstituted aryl group, a substituted or
unsubstituted heterocyclic group, an alkoxy group, a nitro group,
or a substituted or unsubstituted amino group.
[0030] In the case of using the spiro compound of the formula (I-b)
having a silicon atom as a spiro atom, the spiro compound may
preferably be a compound represented by any one of the following
formulas (II-b) to (IX-b): 56
[0031] wherein R.sub.1 to R.sub.4 independently denote a hydrogen
atom, an alkyl group, a substituted or unsubstituted aralkyl group,
a substituted or unsubstituted aryl group, a substituted or
unsubstituted heterocyclic group, an alkoxy group, a nitro group,
or a substituted or unsubstituted amino group.
[0032] In the organic luminescence device of the present invention
at least one of L.sub.1 to L.sub.4 in the formula (I-a) or (I-b)
may preferably be the above-mentioned group represented by any one
of the formulas (X), (XI) and (XII) since the resultant spiro
compound has a high glass transition point to improve a stability
of the organic luminescence device and the resultant emission
wavelength is shifted to a longer wavelength side. Further, in the
organic luminescence device of the present invention, the layer
comprising at least one species of the spiro-compound of the
formula (I-a) or (I-b) may preferably be used as electron injection
layer, an electron-transporting or a luminescence layer.
[0033] Specific examples of the groups represented by K.sub.1 to
K.sub.4, L.sub.1 to L.sub.4 and R.sub.1 to R.sub.21 in the
above-mentioned formula (I-a) to (IX-a), (I-b) to (IX-b) and (X) to
(XII) are enumerated hereinbelow.
[0034] Specific examples of the alkyl group may include: methyl,
ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl, and octyl.
[0035] Specific examples of the aralkyl group may include: benzyl
and phenethyl.
[0036] Specific examples of the aryl group may include: phenyl,
biphenyl, terphenyl, naphthyl, anthryl, phenanthryl, and
fluorenyl.
[0037] Specific examples of heterocyclic group may include:
thienyl, pyrrolyl, imidazolyl, furyl, pyridyl, indolyl, quinolinyl,
and carbazolyl.
[0038] Specific examples of the alkoxyl group may include:
methoxyl, ethoxyl, propoxyl, and phenoxyl.
[0039] Specific examples of the amino group may include:
dimethylamino, diethylamino, dibenzylamino, and diphenylamino.
[0040] Specific examples of the substituents which may be possessed
by the above-mentioned groups may include: alkyl groups, such as
methyl, ethyl and propyl; aralkyl groups, such as benzyl and
phenethyl; aryl groups, such as phenyl, nephthyl and anthryl;
heterocyclic groups, such as thienyl, pyrrolyl, pyridyl and
quinolinyl; and amino groups, such as dimethylamino, diethylamino,
dibenzylamino and diphenylamino.
[0041] Furtheri specific examples of the preferred groups
represented by the above-mentioned formulas (X), (XI) and (XII) as
the groups L.sub.1 to L.sub.4 in the formula (I-a) or (I-b) may
include those (A-1 to A-15) shown below. 789
[0042] Other specific examples of the groups L.sub.1 to L.sub.4 may
include those (B-1 to B-16) shown below. 1011
[0043] Specific examples (Example Compound Nos. a-1 to a-43 and b-1
to b-39) of the Spiro compounds of the formulas (I-a) and (I-b) are
enumerated in Tables 1-16 hereinafter separately for the respective
preferred formulas (II-a) to (IX-a) and (II-b) to (IX-b) wherein
some representative structures for the groups L.sub.1 and L.sub.4
are identified by symbols A-1 to A-15 and B-1 to B-16 shown above,
and "Ph" represents a phenyl group.
[0044] Further, the respective numerals in parentheses for the
groups R.sub.1 to R.sub.4 represent their substitution positions,
respectively, specifically indicated in the formulas (II-a) to
(IX-a) and (II-b) to (IX-b).
[0045] Incidentally, the spiro compounds according to the present
invention inclusive of those enumerated below are synthesized by,
e.g., methods as reported by James M, Tour et al; Journal of
Organic Chemistry, Vol. 61, pp. 6906-(1996) and R. West et al.; J.
Am. Chem. Soc., 124, pp. 49-(2002).
EXAMPLE COMPOUNDS
[0046]
1TABLE 1 Formula (II-a) 12 No. R.sub.1 R.sub.2 R.sub.3 R.sub.4
L.sub.1 L.sub.2 L.sub.3 L.sub.4 a-1 H H H H A-1 A-1 A-1 A-1 a-2 H H
H H A-5 A-5 A-5 A-5 a-3 H H H H A-11 A-11 A-11 A-11 a-4 H H H H
A-14 A-14 A-14 A-14 a-5 CH.sub.3 CH.sub.3 H H H H B-1 B-1 (3) (6)
a-6 H H H H B-2 B-2 B-2 B-2 a-7 H H H H B-3 B-3 B-3 B-3
[0047]
2TABLE 2 Formula (III-a) 13 No. R.sub.1 R.sub.2 R.sub.3 R.sub.4
L.sub.1 L.sub.2 L.sub.3 L.sub.4 a-8 H H H H A-4 A-4 A-4 A-4 a-9 H H
H H A-7 A-7 A-7 A-7 a-10 H H H H A-12 A-12 A-12 A-12 a-11 H H H H
CH.sub.2CH.sub.3 CH.sub.2CH.sub.3 B-4 B-4 a-12 H H H H B-5 B-5 B-5
B-5 a-13 H H H H B-6 B-6 ph ph
[0048]
3TABLE 3 Formula (IV-a) 14 No. R.sub.1 R.sub.2 R.sub.3 R.sub.4
L.sub.1 L.sub.2 L.sub.3 L.sub.4 a-14 H H H H A-2 A-2 A-2 A-2 a-15 H
H H H A-8 A-8 A-8 A-8 a-16 H H H H A-13 A-13 A-13 A-13 a-17 H ph(6)
H ph(6) B-7 H B-7 H a-18 H H H H NO.sub.2 B-8 NO.sub.2 B-8 a-19 H H
H H B-9 B-9 B-9 B-9
[0049]
4TABLE 4 Formula (V-a) 15 No. R.sub.1 R.sub.2 R.sub.3 R.sub.4
L.sub.1 L.sub.2 L.sub.3 L.sub.4 a-20 H H H H A-1 A-1 A-1 A-1 a-21 H
H H H A-3 A-3 A-3 A-3 a-22 H H H H A-6 A-6 A-6 A-6 a-23 H H H H
A-10 A-10 A-10 A-10 a-24 H H H H A-15 A-15 A-15 A-15 a-25 H H H H
B-10 B-10 B-10 B-10 a-26 H H H H B-11 B-11 OCH.sub.3 OCH.sub.3
[0050]
5TABLE 5 Formula (VI-a) 16 No. R.sub.1 R.sub.2 R.sub.3 R.sub.4
L.sub.1 L.sub.2 L.sub.3 L.sub.4 a-27 H H H H A-3 A-3 A-3 A-3 a-28 H
H H H A-7 A-7 A-7 A-7 a-29 H H H H A-15 A-15 A-15 A-15 a-30
CH.sub.3 (3) CH.sub.3 (6) CH.sub.3 (3') CH.sub.3 (6')
(CH.sub.2).sub.3CH.sub.3 (CH.sub.2).sub.3CH.sub.3 B-12 B-12 a-31 H
H H H B-13 B-13 B-13 B-13 a-32 H H H H B-14 B-14 H H
[0051]
6TABLE 6 Formula (VII-a) 17 No. R.sub.1 R.sub.2 R.sub.3 R.sub.4
L.sub.1 L.sub.2 L.sub.3 L.sub.4 a-33 H H H H A-2 A-2 A-2 A-2 a-34 H
H H H A-5 A-5 A-5 A-5 a-35 H H H H A-13 A-13 A-13 A-13 a-36
CH.sub.3 CH.sub.3 H H H H B-15 B-15 (1) (8) a-37 H H H H B-16 B-16
H H
[0052]
7TABLE 7 Formula (VIII-a) 18 No. R.sub.1 R.sub.2 R.sub.3 R.sub.4
L.sub.1 L.sub.2 L.sub.3 L.sub.4 a-38 H H H H A-1 A-1 A-1 A-1 a-39 H
H H H A-4 A-4 A-4 A-4 a-40 H H H H B-1 B-1 B-1 B-1
[0053]
8TABLE 8 Formula (IX-a) 19 No. R.sub.1 R.sub.2 R.sub.3 R.sub.4
L.sub.1 L.sub.2 L.sub.3 L.sub.4 a-41 H H H H A-2 A-2 A-2 A-2 a-42 H
H H H A-6 A-6 A-6 A-6 a-43 H H H H A-12 A-12 A-12 A-12
[0054]
9TABLE 9 Formula (II-b) 20 No. R.sub.1 R.sub.2 R.sub.3 R.sub.4
L.sub.1 L.sub.2 L.sub.3 L.sub.4 b-1 H H H H A-1 A-1 A-1 A-1 b-2 H H
H H A-4 A-4 A-4 A-4 b-3 H H H H A-11 A-11 A-11 A-11 b-4 CH.sub.3
CH.sub.3 CH.sub.3 CH.sub.3 B-1 B-1 B-1 B-1 (3) (6) (3') (6') b-5 H
H H H B-2 B-2 B-2 B-2 b-6 H H H H B-3 B-3 B-3 B-3
[0055]
10TABLE 10 Formula (III-b) 21 No. R.sub.1 R.sub.2 R.sub.3 R.sub.4
L.sub.1 L.sub.2 L.sub.3 L.sub.4 b-8 H H H H A-5 A-5 A-5 A-5 b-9 H H
H H A-6 A-6 A-6 A-6 b-10 H H H H A-12 A-12 A-12 A-12 b-11 H H H H
CH.sub.2CH.sub.3 CH.sub.2CH.sub.3 B-4 B-4 b-12 H H H H B-5 B-5 B-5
B-5 b-13 H H H H B-6 B-6 ph ph
[0056]
11TABLE 11 Formula (IV-b) 22 No. R.sub.1 R.sub.2 R.sub.3 R.sub.4
L.sub.1 L.sub.2 L.sub.3 L.sub.4 b-14 H H H H A-2 A-2 A-2 A-2 b-15 H
H H H A-8 A-8 A-8 A-8 b-16 H H H H A-13 A-13 A-13 A-13 b-17 H H H H
B-7 B-7 B-7 B-7 b-18 H H H H NO.sub.2 NO.sub.2 NO.sub.2 NO.sub.2
b-19 H H H H B-8 B-8 B-8 B-8
[0057]
12TABLE 12 Formula (V-b) 23 No. R.sub.1 R.sub.2 R.sub.3 R.sub.4
L.sub.1 L.sub.2 L.sub.3 L.sub.4 b-20 H H H H A-1 A-1 A-1 A-1 b-21 H
H H H A-3 A-3 A-3 A-3 b-22 H H H H A-10 A-10 A-10 A-10 b-23 H H H H
B-9 B-9 B-9 B-9 b-24 H H H H B-10 B-10 OCH.sub.3 OCH.sub.3
[0058]
13TABLE 13 Formula (VI-b) 24 No. R.sub.1 R.sub.2 R.sub.3 R.sub.4
L.sub.1 L.sub.2 L.sub.3 L.sub.4 b-25 H H H H A-3 A-3 A-3 A-3 b-26 H
H H H A-7 A-7 A-7 A-7 b-27 H H H H A-15 A-15 A-15 A-15 b-28 H H H H
B-11 B-11 B-11 B-11 b-29 H H H H B-12 B-12 H H
[0059]
14TABLE 14 Formula (VII-b) 25 No. R.sub.1 R.sub.2 R.sub.3 R.sub.4
L.sub.1 L.sub.2 L.sub.3 L.sub.4 b-30 H H H H A-2 A-2 A-2 A-2 b-31 H
H H H A-5 A-5 A-5 A-5 b-32 H H H H A-13 A-13 A-13 A-13 b-33
CH.sub.3 CH.sub.3 H H H H B-13 B-13 (1) (8)
[0060]
15TABLE 15 Formula (VIII-b) 26 No. R.sub.1 R.sub.2 R.sub.3 R.sub.4
L.sub.1 L.sub.2 L.sub.3 L.sub.4 b-34 H H H H A-1 A-1 A-1 A-1 b-35 H
H H H A-4 A-4 A-4 A-4 b-36 H H H H B-14 B-14 B-14 B-14
[0061]
16TABLE 16 Formula (IX-b) 27 No. R.sub.1 R.sub.2 R.sub.3 R.sub.4
L.sub.1 L.sub.2 L.sub.3 L.sub.4 b-37 H H H H A-2 A-2 A-2 A-2 b-38 H
H H H A-7 A-7 A-7 A-7 b-39 H H H H A-12 A-12 A-12 A-12
[0062] In the organic luminescence device of the present invention,
the organic compound layer(s) comprising the above-mentioned spiro
compound of the formula (I-a) or (I-b) may be formed between the
pair of anode and cathode (electrodes) by vacuum deposition or
wet-coating process. The organic compound layer(s) may preferably
be formed in a (total) thickness of at most 10 .mu.m, more
preferably at most 0.5 .mu.m, further preferably 0.01-0.5
.mu.m.
[0063] The organic compound layer(s) constituting the organic
luminescence device of the present invention may have a
single-layer structure as shown in FIG. 1 or a laminate structure
of two or more layers as shown in FIGS. 2, 3 and 4.
[0064] More specifically, FIG. 1 is a schematic sectional view
illustrating an embodiment of the organic luminescence device of
the present invention. Referring to FIG. 1, the organic
luminescence device includes a substrate 1, and an anode 2, a
luminescence layer 3 and a cathode disposed in this order on the
substrate 1 so as to form a laminate structure. The luminescence
layer 3 may comprise a single species of luminescent material
exhibiting a hole-transporting function, an electron-transporting
function and a luminescence function in combination or a mixture of
plural compounds exhibiting these functions, respectively. The
luminescence layer 3 may have a thickness of 5 nm to 1 .mu.m,
preferably 10-500 nm.
[0065] FIG. 2 is a sectional view showing a laminate structure of
another embodiment of the organic luminescence device. Referring to
FIG. 2, the organic luminescence device includes a substrate 1, and
an anode 2, a hole-transporting layer 5, an electron-transporting
layer 6 and a cathode 4 disposed successively in this order on the
substrate 1 so as to form a laminate structure. In this case,
either one or both of the hole-transporting layer 5 and the
electron-transporting layer 6 may contain a luminescent material
also having a hole-transporting function and/or an
electron-transporting function, respectively, for constituting a
luminescence layer 3 in combination. One of the layers 6 and 5 may
contain a material having no luminescent function but having a good
electron-transporting or hole-transporting function. Each of the
hole-transporting layer 5 and the electron-transporting layer 6 may
have a thickness of 5 nm to 1 .mu.m, preferably 10-500 nm.
[0066] FIG. 3 is a sectional view showing still another embodiment
of the organic luminescence device of the present invention.
Referring to FIG. 3, the organic luminescence device includes a
substrate 1, and an anode 2, a hole-transporting layer 5, a
luminescence layer 3, an electron-transporting layer 6 and a
cathode 4 disposed successively in this order on the substrate 1 to
form a laminate structure. In this embodiment, the carrier
transporting functions and the luminescent function of the organic
compound layer are separated and assigned to the respective layers.
Each of the hole-transporting layer 5, the luminescence layer 3 and
the electron-transporting layer 6 may contain a single species or
plural species of compounds showing respectively expected functions
so as to exhibit desired performances. More specifically, in the
case of using plural species of compounds in combination, a lot of
latitude is provided in selection of materials for each layer, and
various compounds having different emission wavelengths can be used
to provide a variety of luminescence hues.
[0067] Further, as the carriers and excitons are effectively
confined in the central luminescence layer 3, it is possible to
increase the luminescence efficiency.
[0068] In the embodiment of FIG. 3, each of the hole-transporting
layer 5, the luminescence layer 3 and the electron-transporting
layer 6 may have a thickness of 5 nm-1 .mu.m, preferably 10-500
nm.
[0069] FIG. 4 is a sectional view showing another embodiment of the
organic luminescence device. Referring to FIG. 4, the organic
luminescence device includes a substrate 1, and an anode 2, a
hole-transporting layer 5, an electron-transporting layer 6, an
electron injection layer 7 and a cathode 4 disposed successively in
this order on the substrate 1 so as to form a laminate structure.
The electron injection layer 7 is disposed in order to efficiently
inject electrons from the cathode 4 into the electron-transporting
layer 6, thus functionally separating an electron injection
performance and an electron-transporting performance, respectively,
rom the cathode 4. Each of the hole-transporting layer 5, the
electron-transporting layer 6 and the electron injection layer 7
may have a thickness of 5 nm to 1 .mu.m, preferably 10-500 nm.
[0070] It is to be understood however that FIGS. 1-4 described
above merely show basic structures of the organic luminescence
device according to the present invention, and various
modifications thereof are possible. For example, between the
organic compound layer(s) and the electrodes (anode and cathode),
it is possible to dispose an insulating layer, an adhesive layer,
or an interference layer. Further, the hole-transporting layer 5
can be divided into two layers with different ionization
potentials.
[0071] The spiro compound represented by the formula (I-a) or (I-b)
have better electron injection performance, electron-transporting
performance, luminescence performance and durability than
conventional compounds and can be adopted in any of the device
structures shown in FIGS. 1 to 4.
[0072] The organic compound layer containing the spiro compound of
the formula (I-a) or (I-b) is particularly useful as an electron
injection layer, an electron-transporting layer and/or a
luminescence layer. A layer thereof may be formed by vacuum
deposition or solution coating in a form which is not liable to
crystallize and is excellent in stability with time.
[0073] In the present invention, the Spiro compound of the formula
(I-a) or (I-b) can be used to constitute an electron injection
layer, an electron-transporting layer and/or a luminescence layer,
as desired, in combination with a known hole-transporting compound,
luminescent compound or electron-transporting compound, examples of
which are enumerated hereinbelow. 2829303132333435
[0074] As mentioned above, the organic compound layer(s) containing
the spiro compound of the formula (I-a) or (I-b) or other organic
compound layers may be formed into film by vacuum deposition or
coating of a solution of the relevant compound in an appropriate
solvent. In the case of the solution coating, the organic compound
can be used in mixture with an appropriate binder resin to form a
film.
[0075] The binder resin used for the above purpose may be selected
from a wide variety of scope. Examples thereof may include:
polyvinyl carbazole resin, polycarbonate resin, polyester resin,
polyarylate resin, polystyrene resin, acrylic resin, methacrylic
resin, butyral resin, polyvinyl acetal resin, diallyl phthalate
resin, phenolic resin, epoxy resin, silicone resin, polysulfone
resin, and urea resin. These resins may be used singly or in
combination of two or more species or in the form of
copolymers.
[0076] As a material for the anode (2 shown in FIGS. 1 -4), it is
preferred to use one having as large a work function as possible,
examples of which may include: metals, such as gold, platinum,
nickel, palladium, cobalt, selenium and vanadium, and their alloys;
metal oxides, such as tin oxide, zinc oxide, indium tin oxide
(ITO), and indium zinc oxide; and electroconductive polymers, such
as polyaniline, polypyrrole, polythiophene, and polyphenylene
sulfide. These compounds may be used singly or in combination of
two or more species.
[0077] On the other hand, as a material for the cathode 4 shown in
FIGS. 1-4, it is preferred to use one having a small work function,
examples of which may include: metals, such as lithium, sodium,
potassium, calcium, magnesium, aluminum, indium, silver, lead, tin
and chromium, and their alloys. It is also possible to use metal
oxide, such as indium tin oxide (ITO). The cathode may be formed in
a single layer or a lamination of plural layers.
[0078] The substrate 1 shown in FIGS. 1-4 for the organic
luminescence device of the present invention may include an opaque
substrate of metal, ceramics, etc., and a transparent substrate of
glass, quartz, plastics, etc. It is possible to form the substrate
with a color filter film, a fluorescent color conversion film, a
dielectric reflection film, etc., thus controlling emitted
luminescent light.
[0079] In order to prevent contact with oxygen and/or moisture, the
organic luminescence device of the present invention may further
include a protective layer or a sealing layer. Examples of the
protective layer may include: an inorganic film of diamond, metal
oxide, metal nitride, etc.; a polymer film of fluorine-containing
resin, polyparaxylene, polyethylene, silicone resin, polystyrene,
etc., and a film of light-curable resin. It is also possible to
effect packaging of the organic luminescence device per se with a
sealing resin while covering the organic luminescence device with
glass, gas-impermeable film, metal, etc.
[0080] Hereinbelow, the present invention will be described more
specifically based on Examples.
EXAMPLE A-1
[0081] An electroluminescence device of a structure as shown in
FIG. 2 was prepared in the following manner.
[0082] A 0.7 mm-thick glass substrate (substrate 1) coated with a
120 nm-thick film of ITO (indium tin oxide) (anode 2) formed by
sputtering was successively washed with acetone and isopropyl
alcohol (IPA) under application of ultrasonic wave and then washed
with IPA under boiling, followed by cleaning by UV/ozone (i.e.,
irradiation with ultraviolet rays in the ozone-containing
atmosphere), to obtain a transparent conductive substrate
(including the substrate 1 and the ITO anode 2 formed thereon).
[0083] The transparent conductive substrate was coated by vacuum
deposition of a compound (TPD) represented by a structural formula
shown below: 36
[0084] to form a 70 nm-thick hole-transporting layer 5 and then by
vacuum deposition of a spiro compound (Example Compound No. a-1
listed in Table 1) to form a 70 nm-thick electron-transporting
layer 6. The vacuum deposition was respectively performed in a
vacuum of 1.0.times.10.sup.-5 Pa and at a film thickness growth
rate of 0.2-0.3 nm/sec.
[0085] Then, the electron-transporting layer 6 was further coated
by vacuum deposition of Al--Li alloy (Li content: 1 atom %) to form
a 150 nm-thick metal film (cathode 4) under a vacuum of
1.0.times.10.sup.-4 Pa and at a film thickness growth rate of
1.0-1.2 nm/sec, thereby forming an organic luminescence device of a
structure shown in FIG. 2.
[0086] The thus-obtained device was then supplied with a DC voltage
of 8 volts between the ITO electrode 2 as an anode and the Al--Li
alloy electrode 4 as a cathode, whereby a current flowed at a
density of 8.5 mA/cm.sup.2 and red luminescence was observed at a
luminance of 600 cd/m.sup.2. The device was further subjected to
100 hours of continuous voltage application at a constant current
density of 7.0 mA/cm.sup.2 in a nitrogen atmosphere, whereby the
device initially exhibited a luminance of 520 cd/m.sup.2, which was
lowered to 490 cd/m.sup.2 after 100 hours, thus showing only a
small luminance deterioration.
[0087] The results are shown in Table 17 set forth hereinafter.
EXAMPLE A-2 to A-20
[0088] Organic luminescence devices were prepared and evaluated in
the same manner as in Example A-1 except for replacing the Spiro
compound (Ex. Comp. No. a-1) with those shown in Table 17,
respectively.
[0089] The results are inclusively shown in Table 17 set forth
hereinafter.
COMPARATIVE EXAMPLES A-1 to A-3
[0090] Comparative organic luminescence devices were prepared and
evaluated in the same manner as in Example A-1 except for using
Comparative Compound Nos. 1-3, respectively, shown below, instead
of the spiro compound (Ex. Comp. No. a-1). The results are also
shown in Table 17. 37
17TABLE 17 Luminance Example Initial (at 7.0 mA/cm.sup.2) Exam-
Compound Voltage Luminance Initial After 100 ple No. (V)
(cd/m.sup.2) (cd/m.sup.2) hrs. (cd/m.sup.2) A-1 a-1 8 600 520 490 2
a-4 8 540 500 460 3 a-7 8 340 290 240 4 a-9 8 440 400 360 5 a-10 8
530 495 460 6 a-13 8 200 165 135 7 a-14 8 565 510 475 8 a-17 8 180
150 120 9 a-21 8 420 385 335 10 a-22 8 470 430 385 11 a-26 8 190
140 115 12 a-27 8 515 475 440 13 a-29 8 530 495 460 14 a-32 8 195
160 135 15 a-33 8 560 485 445 16 a-36 8 160 140 115 17 a-38 8 530
480 440 18 a-40 8 170 145 105 19 a-42 8 450 415 380 20 a-43 8 525
480 450 Comp. Comp. 8 20 15 ** A-1 No. 1 Comp. Comp. 8 60 40 10 A-2
No. 2 Comp. Comp. 8 15 10 ** A-3 No. 3 **: No luminescence
EXAMPLE A-21
[0091] The procedure of Example A-1 was repeated up to the
formation of the hole-transporting layer 5.
[0092] Then, the hole-transporting layer 5 was further coated by
vacuum deposition of a mixture of spiro compound (Ex. Compound No.
a-2) and aluminum tris(quinolinol) in a weight ratio of 1:20 to
form a 70 nm-thick electron-transporting layer 6 under a vacuum of
1.0.times.10.sup.-4 Pa and at a film thickness growth rate of
0.2-0.3 nm/sec.
[0093] Then, the electron-transporting layer 6 was further coated
by vacuum deposition of Al--Li alloy (Li content: 1 atom. %) to
form a 150 nm-thick metal film 4 under a vacuum of
1.0.times.10.sup.-4 Pa and at a film thickness growth rate of
1.0-1.2 nm/sec, thereby forming an organic luminescence device of a
structure shown in FIG. 2.
[0094] The thus-obtained device was then supplied with a DC voltage
of 8 volts between the ITO electrode 2 as an anode and the Al--Li
alloy electrode 4 as a cathode, whereby a current flowed at a
density of 9.0 mA/cm.sup.2 and orange luminescence was observed at
a luminance of 830 cd/m.sup.2. The device was further subjected to
100 hours of continuous voltage application at a constant current
density of 7.0 mA/cm.sup.2 in a nitrogen atmosphere, whereby the
device initially exhibited a luminance of 640 cd/m.sup.2, which was
lowered to 590 cd/m .sup.2 after 100 hours, thus showing only a
small luminance deterioration.
[0095] The results are shown in Table 18 set forth hereinafter.
EXAMPLES A-22 to A-32
[0096] Organic luminescence devices were prepared and evaluated in
the same manner as in Example A-21 except for replacing the spiro
compound (Ex. Comp. No. a-2) with those shown in Table 18,
respectively.
[0097] The results are inclusively shown in Table 18 set forth
hereinafter.
COMPARATIVE EXAMPLES A-4 to A-6
[0098] Comparative organic compound devices were prepared and
evaluated in the same manner as in Example A-21 except for using
Comparative Compound Nos. 1-3, respectively, shown above, instead
of the spiro compound (Ex. Comp. No. a-2). The results are also
shown in Table 18.
18 TABLE 18 Luminance Initial (at 7.0 mA/cm.sup.2) Exam- Compound
Voltage Luminance Initial After 100 ple No. (V) (cd/m.sup.2)
(cd/m.sup.2) hrs. (cd/m.sup.2) A-21 a-2 8 830 640 590 22 a-5 8 540
480 435 23 a-11 8 505 460 430 24 a-15 8 590 520 475 25 a-18 8 490
455 405 26 a-20 8 1020 810 750 27 a-23 8 800 610 570 28 a-25 8 530
480 440 29 a-30 8 480 445 400 30 a-34 8 780 600 565 31 a-37 8 530
500 455 32 a-39 8 680 580 540 Comp. Comp. 8 240 200 110 A-4 No. 1
Comp. Comp. 8 300 240 95 A-5 No. 2 Comp. Comp. 8 245 200 40 A-6 No.
3
EXAMPLE A-33
[0099] The procedure of Example A-1 was repeated up to the
formation of the hole-transporting layer 5.
[0100] Then, the hole-transporting layer 5 was further coated by
vacuum deposition of aluminum tris(quinolinol) to form a 30
nm-thick luminescence layer 3 and then by vacuum deposition of a
spiro compound (Ex. Compound No. a-8) to form a 50 nm-thick
electron-transporting layer 6, respectively under a vacuum of
1.0.times.10.sup.-4 Pa and at a film thickness growth rate of
0.2-0.3 nm/sec.
[0101] Then, the electron-transporting layer 6 was further coated
by vacuum deposition of Al--Li alloy (Li content: 1 atom. %) to
form a 150 nm-thick metal film 4 under a vacuum of
1.0.times.10.sup.-4 Pa and at a film thickness growth rate of
1.0-1.2 nm/sec, thereby forming an organic luminescence device of a
structure shown in FIG. 3.
[0102] The thus-obtained device was then supplied with a DC voltage
of 10 volts between the ITO electrode 2 as an anode and the Al-Li
alloy electrode 4 as a cathode, whereby a current flowed at a
density of 12.0 mA/cm.sup.2 and yellow luminescence was observed at
a luminance of 1270 cd/m.sup.2. The device was further subjected to
100 hours of continuous voltage application at a constant current
density of 10.0 mA/cm.sup.2 in a nitrogen atmosphere, whereby the
device initially exhibited a luminance of 1080 cd/m.sup.2, which
was lowered to 990 cd/m.sup.2 after 100 hours, thus showing only a
small luminance deterioration.
[0103] The results are shown in Table 19 set forth hereinafter.
EXAMPLES A-34 to A-43
[0104] Organic luminescence devices were prepared and evaluated in
the same manner as in Example A-33 except for replacing the spiro
compound of (Ex. Comp. No. a-8) with those show in Table 19,
respectively.
[0105] The results are inclusively shown in Table 19 set forth
hereinafter.
COMPARATIVE EXAMPLES A-7 to A-9
[0106] Comparative organic luminescence devices were prepared and
evaluated in the same manner as in Example A-33 except for using
Comparative Compound Nos. 1-3, respectively, shown above, instead
of the spiro compound Ex. Comp. No. a-8. The results are also shown
in Table 19.
19 TABLE 19 Luminance Initial (at 10.0 mA/cm.sup.2) Exam- Compound
Voltage Luminance Initial After 100 ple No. (V) (cd/m.sup.2)
(cd/m.sup.2) hrs. (cd/m.sup.2) A-33 a-8 10 1270 1080 990 34 a-3 10
1100 930 860 35 a-6 10 860 720 640 36 a-12 10 870 730 660 37 a-16
10 1030 900 820 38 a-19 10 830 690 650 39 a-24 10 1280 1120 1010 40
a-28 10 1070 920 860 41 a-31 10 900 760 700 42 a-35 10 1150 970 910
43 a-41 10 1440 1230 1130 Comp. Comp. 10 120 100 30 A-7 No. 1 Comp.
Comp. 10 160 130 45 A-8 No. 2 Comp. Comp. 10 50 35 ** A-9 No. 3 **:
No luminescence.
EXAMPLE A-44
[0107] A transparent conductive substrate prepared and treated for
cleaning in the same manner as in Example A-1 was coated with a
solution of 0.050 g of a spiro compound (Ex. Comp. No. a-1) and
1.00 g of poly-N-vinylcarbazole (weight-average molecular
weight=63,000) in 80 ml of chloroform by spin coating at a rate of
2000. rpm, followed by drying, to form a 120 nm-thick luminescence
layer 3.
[0108] Then, the luminescence layer 3 was further coated by vacuum
deposition of Al--Li alloy (Li content: 1 atom %) to form a 150
nm-thick metal film 4 under a vacuum of 1.0.times.10.sup.-4 Pa and
at a film thickness growth rate of 1.0-1.2 nm/sec, thereby forming
an organic luminescence device of a structure shown in FIG. 1.
[0109] The thus-obtained device was then supplied with a DC voltage
of 10 volts between the ITO electrode 2 as an anode and the Al--Li
alloy electrode 4 as a cathode, whereby a current flowed at a
density of 9.5 mA/cm.sup.2 and red luminescence was observed at a
luminance of 450 cd/m.sup.2.
COMPARATIVE EXAMPLE A-10
[0110] An organic luminescence device was prepared in the same
manner as in Example A-44 except for using Comparative Compound No.
2 instead of the spiro compound Ex. Comp. No. a-1.
[0111] The resultant device was similarly supplied with a DC
voltage of 10 volts, whereby a current followed at a density of 9.0
mA/cm.sup.2 and yellow-green luminescence was observed at a
luminance of 30 cd/m.sup.2.
EXAMPLE B-1
[0112] An electroluminescence device of a structure as shown in
FIG. 2 was prepared in the following manner.
[0113] A 0.7 mm-thick glass substrate (substrate 1) coated with a
120 nm-thick film of ITO (indium tin oxide) (anode 2) formed by
sputtering was successively washed with acetone and isopropyl
alcohol (IPA) under application of ultrasonic wave and then washed
with IPA under boiling, followed by cleaning by UV/ozone (i.e.,
irradiation with ultraviolet rays in the ozone-containing
atmosphere), to obtain a transparent conductive substrate
(including the substrate 1 and the ITO anode 2 formed thereon).
[0114] The transparent conductive substrate was coated by vacuum
deposition of a compound (TPD) represented by a structural formula
shown below: 38
[0115] to form a 70 nm-thick hole-transporting layer 5 and then by
vacuum deposition of a spiro compound (Example Compound No. b-1
listed in Table 9) to form a 70 nm-thick electron-transporting
layer 6. The vacuum deposition was respectively performed in a
vacuum of 1.0.times.10.sup.-4 Pa and at a film thickness growth
rate of 0.2-0.3 nm/sec.
[0116] Then, the electron-transporting layer 6 was further coated
by vacuum deposition of Al--Li alloy (Li content: 1 atom %) to form
a 150 nm-thick metal film (cathode 4) under a vacuum of
1.0.times.10.sup.-4 Pa and at a film thickness growth rate of
1.0-1.2 nm/sec, thereby forming an organic luminescence device of a
structure shown in FIG. 2.
[0117] The thus-obtained device was then supplied with a DC voltage
of 8 volts between the ITO electrode 2 as an anode and the Al--Li
alloy electrode 4 as a cathode, whereby a current flowed at a
density of 8.0 mA/cm.sup.2 and red luminescence was observed at a
luminance of 560 cd/m.sup.2. The device was further subjected to
100 hours of continuous voltage application at a constant current
density of 7.0 mA/cm.sup.2 in a nitrogen atmosphere, whereby the
device initially exhibited a luminance of 510 cd/m.sup.2, which was
lowered to 485 cd/m.sup.2 after 100 hours, thus showing only a
small luminance deterioration.
[0118] The results are shown in Table 20 set forth hereinafter.
EXAMPLES B-2 to B-17
[0119] Organic luminescence devices were prepared and evaluated in
the same manner as in Example B-1 except for replacing the spiro
compound (Ex. Comp. No. b-1) with those shown in Table 20,
respectively.
[0120] The results are inclusively shown in Table 20 set forth
hereinafter.
COMPARATIVE EXAMPLES B-1 and B-2
[0121] Comparative organic luminescence devices were prepared and
evaluated in the same manner as in Example B-1 except for using
Comparative Compound Nos. 1 and 2, respectively, shown below,
instead of the spiro compound (Ex. Comp. No. b-1). The results are
also shown in Table 20. 39
20TABLE 20 Luminance Example Initial (at 7.0 mA/cm.sup.2) Exam-
Compound Voltage Luminance Initial After 100 ple No. (V)
(cd/m.sup.2) (cd/m.sup.2) hrs. (cd/m.sup.2) B-1 b-1 8 560 510 485 2
b-3 8 540 500 470 3 b-7 8 350 310 245 4 b-9 8 530 480 455 5 b-10 8
535 495 460 6 b-12 8 230 210 190 7 b-14 8 590 540 495 8 b-17 8 190
160 140 9 b-21 8 490 470 435 10 b-23 8 370 330 285 11 b-26 8 490
460 415 12 b-27 8 510 475 440 13 b-29 8 230 195 160 14 b-31 8 500
460 430 15 b-33 8 260 230 200 16 b-35 8 490 460 420 17 b-38 8 530
490 445 Comp. Comp. 8 20 15 ** B-1 No. 1 Comp. Comp. 8 60 40 10 B-2
No. 2 **: No luminescence
EXAMPLE B-21
[0122] The procedure of Example B-1 was repeated up to the
formation of the hole-transporting layer 5.
[0123] Then, the hole-transporting layer 5 was further coated by
vacuum deposition of a mixture of spiro compound (Ex. Compound No.
b-2) and aluminum tris(quinolinol) in a weight ratio of 1:20 to
form a 70 nm-thick electron-transporting layer 6 under a vacuum of
1.0.times.10.sup.-4 Pa and at a film thickness growth rate of
0.2-0.3 nm/sec.
[0124] Then, the electron-transporting layer 6 was further coated
by vacuum deposition of Al--Li alloy (Li content: 1 atom. %) to
form a 150 nm-thick metal film 4 under a vacuum of
1.0.times.10.sup.-4 Pa and at a film thickness growth rate of
1.0-1.2 nm/sec, thereby forming an organic luminescence device of a
structure shown in FIG. 2.
[0125] The thus-obtained device was then supplied with a DC voltage
of 8 volts between the ITO electrode 2 as an anode and the Al--Li
alloy electrode 4 as a cathode, whereby a current flowed at a
density of 8.5 mA/cm.sup.2 and orange luminescence was observed at
a luminance of 800 cd/m.sup.2. The device was further subjected to
100 hours of continuous voltage application at a constant current
density of 7.0 mA/cm.sup.2 in a nitrogen atmosphere, whereby the
device initially exhibited a luminance of 620 cd/m.sup.2, which was
lowered to 590 cd/m.sup.2 after 100 hours, thus showing only a
small luminance deterioration.
[0126] The results are shown in Table 21 set forth hereinafter.
EXAMPLES B-19 to B-28
[0127] Organic luminescence devices were prepared and evaluated in
the same manner as in Example B-18 except for replacing the spiro
compound (Ex. Comp. No. b-2) with those shown in Table 21,
respectively.
[0128] The results are inclusively shown in Table 21 set forth
hereinafter.
COMPARATIVE EXAMPLES B-3 and B-4
[0129] Comparative organic compound devices were prepared and
evaluated in the same manner as in Example B-18 except for using
Comparative Compound Nos. 1 and 2, respectively, shown above,
instead of the spiro compound (Ex. Comp. No. b-2). The results are
also shown in Table 21.
21 TABLE 21 Luminance Initial (at 7.0 mA/cm.sup.2) Exam- Compound
Voltage Luminance Initial After 100 ple No. (V) (cd/m.sup.2)
(cd/m.sup.2) hrs. (cd/m.sup.2) B-18 b-2 8 800 620 590 19 b-5 8 530
470 430 20 b-8 8 780 600 560 21 b-11 8 490 455 405 22 b-15 8 790
630 595 23 b-20 8 980 800 750 24 b-25 8 830 630 600 25 b-30 8 800
600 540 26 b-34 8 780 600 565 27 b-37 8 770 600 560 28 b-39 8 810
610 555 Comp. Comp. 8 240 200 110 B-3 No. 1 Comp. Comp. 8 300 240
95 B-4 No. 2
EXAMPLE B-29
[0130] The procedure of Example B-1 was repeated up to the
formation of the hole-transporting layer 5.
[0131] Then, the hole-transporting layer 5 was further coated by
vacuum deposition of aluminum tris(quinolinol) to form a 30
nm-thick luminescence layer 3 and then by vacuum deposition of a
spiro compound (Ex. Compound No. b-4) to form a 50 nm-thick
electron-transporting layer 6, respectively under a vacuum of
1.0.times.10.sup.-4 Pa and at a film thickness growth rate of
0.2-0.3 nm/sec.
[0132] Then, the electron-transporting layer 6 was further coated
by vacuum deposition of Al--Li alloy (Li content: 1 atom. %) to
form a 150 nm-thick metal film 4 under a vacuum of
1.0.times.10.sup.-4 Pa and at a film thickness growth rate of
1.0-1.2 nm/sec, thereby forming an organic luminescence device of a
structure shown in FIG. 3.
[0133] The thus-obtained device was then supplied with a DC voltage
of 10 volts between the ITO electrode 2 as an anode and the Al--Li
alloy electrode 4 as a cathode, whereby a current flowed at a
density of 11.0 mA/cm.sup.2 and yellow luminescence was observed at
a luminance of 1050 cd/m.sup.2. The device was further subjected to
100 hours of continuous voltage application at a constant current
density of 10.0 mA/cm.sup.2 in a nitrogen atmosphere, whereby the
device initially exhibited a luminance of 980 cd/m.sup.2, which was
lowered to 930 cd/m.sup.2 after 100 hours, thus showing only a
small luminance deterioration.
[0134] The results are shown in Table 22 set forth hereinafter.
EXAMPLES B-30 to B-39
[0135] Organic luminescence devices were prepared and evaluated in
the same manner as in Example B-29 except for replacing the spiro
compound of (Ex. Comp. No. b-4) with those show in Table 22,
respectively.
[0136] The results are inclusively shown in Table 22 set forth
hereinafter.
COMPARATIVE EXAMPLES B-5 to B-6
[0137] Comparative organic luminescence devices were prepared and
evaluated in the same manner as in Example B-29 except for using
Comparative Compound Nos. 1 and 2, respectively, shown above,
instead of the spiro compound Ex. Comp. No. b-4. The results are
also shown in Table 22.
22 TABLE 22 Luminance Initial (at 10.0 mA/cm.sup.2) Exam- Compound
Voltage Luminance Initial After 100 ple No. (V) (cd/m.sup.2)
(cd/m.sup.2) hrs. (cd/m.sup.2) B-29 b-4 10 1050 990 930 30 b-6 10
830 700 640 31 b-13 10 870 730 660 32 b-16 10 1010 930 860 33 b-18
10 850 710 630 34 b-19 10 820 690 640 35 b-22 10 1120 1040 950 36
b-28 10 790 700 630 37 b-32 10 1000 960 920 38 b-34 10 1050 960 910
39 b-36 10 800 710 640 Comp. Comp. 10 120 100 30 B-5 No. 1 Comp.
Comp. 10 160 130 45 B-6 No. 2
EXAMPLE B-40
[0138] A transparent conductive substrate prepared and treated for
cleaning in the same manner as in Example B-1 was coated with a
solution of 0.050 g of a spiro compound (Ex. Comp. No. b-1) and
1.00 g of poly-N-vinylcarbazole (weight-average molecular
weight=63,000) in 80 ml of chloroform by spin coating at a rate of
2000 rpm, followed by drying, to form a 120 nm-thick luminescence
layer 3.
[0139] Then, the luminescence layer 3 was further coated by vacuum
deposition of Al--Li alloy (Li content: 1 atom %) to form a 150
nm-thick metal film 4 under a vacuum of 1.0.times.10.sup.-4 Pa and
at a film thickness growth rate of 1.0-1.2 nm/sec, thereby forming
an organic luminescence device of a structure shown in FIG. 1.
[0140] The thus-obtained device was then supplied with a DC voltage
of 10 volts between the ITO electrode 2 as an anode and the Al--Li
alloy electrode 4 as a cathode, whereby a current flowed at a
density of 9.0 mA/cm.sup.2 and orange luminescence was observed at
a luminance of 410 cd/m.sup.2.
COMPARATIVE EXAMPLE B-7
[0141] An organic luminescence device was prepared in the same
manner as in Example B-40 except for using Comparative Compound No.
2 instead of the spiro compound Ex. Comp. No. b-1.
[0142] The resultant device was similarly supplied with a DC
voltage of 10 volts, whereby a current followed at a density of 9.0
mA/cm.sup.2 and yellow-green luminescence was observed at a
luminance of 30 cd/m.sup.2.
[0143] Industrial Applicability
[0144] As described above, the organic luminescence device
according to the present invention using a spiro compound
represented by the above-mentioned formula (I-a) or (I-b) produces
high-luminance luminescence at a low applied voltage and is
excellent in durability. Particularly, an organic layer using the
spiro compound of formula (I-a) or (I-b) is suitable for an
electron-transporting layer or a luminescence layer constituting an
organic luminescence device. Further, it is possible to produce the
organic luminescence device through vacuum deposition, casting,
wet-coating (e.g., spin coating), etc., thus readily realizing a
large-size organic luminescence device relatively
inexpensively.
* * * * *